Low lead piezoelectric ceramics material of a kind of high curie point and preparation method thereof
Technical field
The present invention relates to low lead piezoelectric ceramics material of a kind of high curie point and preparation method thereof, belong to the function ceramics applied technical field.
Background technology
Pb (Zr, Ti) O
3Base pottery (PZT) belongs to ABO
3The type perovskite structural material has excellent piezoelectric property, its Curie temperature height, and piezoelectricity is strong, and good stability has a wide range of applications in fields such as transmitter, piezoelectric transformer, ultrasonic transducer, resonator, ignition and blasting device, ultrasonic delay lines.But the preparation of PZT pottery needs a large amount of lead oxidess that contains, its production process and offal treatment stage all bring certain harm to environment, and along with science and technology development, the Curie-point temperature of PZT has been difficult to satisfy the demand in fields such as aerospace, petrochemical industry metallurgy.The particularly requirement in fields such as high temperature jerkmeter, pyrostat, vortex shedding flow meter.Therefore the low plumbous good high curie point piezoelectric ceramics of environment compatibility of exploitation is a problem with great realistic meaning.
PZT is ceramic modified to be the hot subject in piezoelectricity field always, and people such as USSR (Union of Soviet Socialist Republics) scientist G.A.Smlensky have studied A (B
1/2B '
1/2) O
3Type and A (B
1/3B '
2/3) O
3The composite perofskite type material, the elements compounding of discovery employing different valence state replaces A, the B position ion in the perovskite structure, not only can increase the degree of freedom of regulating the piezoelectric ceramics performance, and has greatly enriched the kind of piezoelectric ceramics.
The Bi sill is compared with the material of Pb base, and very strong piezoelectricity and very high polarization are arranged, and environmental harmony is also better.We can carry out the A position to PZT in view of the above and replace the B position, come modification to form new sosoloid, because Bi
3+With Pb
2+Have identical outer stable electrical minor structure, and Bi there are higher ionic valence condition and less ionic radius, the PbTiO that makes the Bi modification
3Series has more stable chemical bonding structure and stronger chemical b `, thereby makes the Curie temperature of total system be improved.
Summary of the invention
The objective of the invention is to utilize Bi and composite perofskite type compound (Ti, Zn etc.) to ABO
3The PbTiO of type perovskite structure
3In Pb carry out the part substituting modification, adopt template grain growth (TGG), with the SrTiO of sheet perovskite structure
3As mould material, comprehensive utilization crystal grain orienting technology, flow casting molding and isostatic cool pressing processing method prepare a kind of novel piezoceramic material with high-curie temperature.
The objective of the invention is to be achieved through the following technical solutions:
High curie point hangs down the lead piezoelectric ceramics preparation methods, is to adopt template grain growth (TGG), with the SrTiO of sheet perovskite structure
3As mould material, comprehensive utilization crystal grain orienting technology, flow casting molding and isostatic cool pressing processing method, concrete grammar is as follows:
1) adopts molten-salt growth method synthesizing flaky SrTiO
3Crystal is mainly finished by two steps, at first at 1150 ℃, and synthesizing flaky presoma Sr in the fusing assistant KCl/NaCl fused salt mixt
3Ti
2O
7, and then pass through SrTiO
3Growth unit is at the tabular crystal Sr of the first step acquisition
3Ti
2O
7On carry out growing and preparing and go out flaky SrTiO
3Crystal.
2) get the Bi of 500-800g
2O
3, TiO
2, ZnO, PbO, press Bi (Zn
1/2Ti
1/2) O
3-PbTiO
3Mixed carry out pre-burning together, stoichiometric ratio is 1: 3: 1: 2.
3) with the SrTiO that makes
3Template and BZT-PT powder are as the powder of preparation casting slurry, add solvent, dispersion agent, binding agent and plastic agent, prepared slurry is through curtain coating, the dry biscuit that obtains afterwards, the curtain coating biscuit is cut, carries out sintering after lamination, isostatic cool pressing and the plastic removal, obtain piezoceramic material.
Effect of the present invention is: substitute part Pb with Bi in preparation process, not only can effectively reduce the content of Pb in the pottery, increase the environment compatibility of piezoelectric ceramics, but also increased the Curie temperature of material, expanded its use range.Can be widely used in fields such as space flight, petrochemical industry, metallurgy, geological prospecting.
Embodiment
The invention will be further described below in conjunction with embodiment:
Embodiment 1
At 1150 ℃, synthetic 3h in the fusing assistant KCl/NaCl fused salt mixt, preparation sheet SrTiO
3Crystal.
Get 235gBi
2O
3, 120gTiO
2, 40.5gZnO, 245gPbO.Press Bi (Zn
1/2Ti
1/2) O
3-PbTiO
3Stoichiometric ratio mix and carry out pre-burning, temperature is 850 ℃ to 1000 ℃, wherein Bi is excessive 5%, Pb is excessive 10%, in order to the volatilization of Bi and Pb in the compensation sintering.
With the SrTiO that makes
3Template and BZT-PT powder are as the powder of preparation casting slurry, adding 300-350g ethanol is that dispersion agent, 60-70g polyvinyl butyral are that binding agent and 30-35g dibutyl phthalate are plastic agent as solvent, 12-15g triolein, prepared slurry is through obtaining biscuit after 600 μ m curtain coatings, 45 ℃ of dry 12h, with curtain coating biscuit 200MPa isostatic cool pressing 10min, carry out sintering after 500 ℃ of plastic removal 24h, obtain piezoelectric ceramics.
Embodiment 2
At 1150 ℃, synthetic 3h in the fusing assistant KCl/NaCl fused salt mixt, preparation sheet SrTiO
3Crystal.
Get 188gBi
2O
3, 96gTiO
2, 32.4gZnO, 196gPbO.Press Bi (Zn
1/2Ti
1/2) O
3-PbTiO
3Stoichiometric ratio mix and carry out pre-burning, temperature is 850 ℃ to 1000 ℃, wherein Bi is excessive 5%, Pb is excessive 10%, in order to the volatilization of Bi and Pb in the compensation sintering.
With the SrTiO that makes
3Template and BZT-PT powder are as the powder of preparation casting slurry, and adding 200g-300g ethanol and butanone mixed solvent is 2: 1 as solvent, ratio.The 8-12g triolein is that dispersion agent, 50-60g polyvinyl butyral are that binding agent and 20-30g dibutyl phthalate, polyoxyethylene glycol mixed solution are plastic agent, prepared slurry is through obtaining biscuit after 500 μ m curtain coatings, 45 ℃ of dry 12h, with curtain coating biscuit 200MPa isostatic cool pressing 10min, carry out sintering after 500 ℃ of plastic removal 24h, obtain piezoelectric ceramics.